


The Old Switcheroo

by sup_ma_boi



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alternate Universe - Canon Divergence, Anal Fingering, Anal Sex, Begging, Bottom Eren Yeager, Cute Eren Yeager, Gay, Gay Sex, Kissing, M/M, Nonbinary Hange Zoë, One Shot, Orgasm Delay/Denial, POV Levi (Shingeki no Kyojin), Short Eren Yeager, Tall Levi (Shingeki no Kyojin), Top Levi (Shingeki no Kyojin)
Language: English
Status: Completed
Published: 2020-11-07
Updated: 2020-11-07
Packaged: 2021-03-08 17:55:42
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,113
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27440800
Author URL: https://archiveofourown.org/users/sup_ma_boi/pseuds/sup_ma_boi
Summary: When Hanji accidentally switches Levi and Eren's heights, they order for Levi and Eren to stay together until they can find a way to change them back.
Relationships: Levi/Eren Yeager
Comments: 5
Kudos: 341





	The Old Switcheroo

"Shitty Glasses, what did you  _ do _ ?" Levi growls, grabbing the deranged scientist by their collar and lifting them to his new height. 

At about sunrise that morning, Levi had gotten out of bed and hit his head on the cabinet that he usually isn't tall enough to reach. When he tried to look in his full-body mirror, he could only see his legs and torso. When he tried to get dressed, all of his clothes were too short. 

It's a miracle that he hadn't found Hanji earlier in the day. 

"I didn't  _ mean  _ to do anything! I was just doing a side-by-side comparison of some of your DNA with Eren's!"

"So how the hell do you explain me growing damn near a foot?"

"I don't know!"

Suddenly, the door to Hanji's lab is slammed open.

"Squad Leader Hanji? I'm short!" the concerned voice of a certain brunet rings out. Both adults turn to look at him, both of their eyes going wide.

The brunet, who usually stands at around 5'7, stands in the doorway at a staggering height of about 5'3. Levi figures that all of Eren's clothes are too big since the kid is only wearing a shirt that reaches all the way to the middle of his thick, tan thighs. 

"Am I... interrupting something, sir?" Eren asks, ready to close the door. Levi sighs and throws Hanji onto the floor. 

"You're not interrupting anything except for me about to kill Shitty Glasses."

"It was an accident! You should be  _ glad  _ that whatever I did happened since you actually  _ grew  _ and your little boy crush is-- Ow!" 

"None of my clothes fit, dimwit."

"None of my clothes fit either," Eren mumbles as he pulls the hem of his shirt down. Levi wants to smirk at Eren's cute nervousness. He would have had he not been pissed with Shitty Glasses, so he opts for his usual dry humor instead. 

"I'd say you could borrow some of mine, but I don't think your ass will fit into any of my pants."

Eren blushes darkly, casting his gaze toward the floor.

"Well, until I can get this fixed," Hanji interrupts, standing up and wiping the dirt off their pants, "I'll need you both to take time off. I don't want you two on any expeditions in case the changes in heights have affected your fighting abilities."

"So what are we supposed to do for the next however long?" the raven asks, folding his arms. 

"I don't know. Just wait for me to figure out how to solve this. And stay together."

"What the hell do you mean 'stay together'?"

"If I figure out how to fix this, I don't want to have to work my ass off to get you to in the same vicinity."

"What the hell do you mean  _ if  _ ?" 

"Just stay together! And get out so I can start working on a solution!" Hanji orders, pushing the two men out of their office. "And don't come back until I'm done!"

With those words, Hanji slams the door and locks it. Levi wants to kick the door down and choke the life out of Shitty Glasses, but that would be unwise as they are the only person who can possibly get him back to normal. 

Instead, he turns to Eren, enjoying how he has to look down to stare the brunet in his eyes. He'd never seen Eren from this angle, so he is pleasantly surprised at how... submissive Eren looks, eyes on the floor as he fiddles with his shirt. 

"Look up at me," Levi commands. 

Eren slowly tilts his head up, blinking up at his Captain with eyes the size of saucers. Their green hue shines so brightly in the dim hallway, giving his eyes a jewel-like appearance. His long eyelashes bat up at the now taller man, making Levi's heart skip a beat.

"It seems like we'll be stuck together for a while. As long as you're not as annoying as Shitty Glasses, you and I should get along just fine. We'll sleep in my quarters. I'm not sleeping in that dusty ass dungeon. And don't go all titan on me either because I won't hesitate to kill you."

"Yes, sir," Eren mumbles in response. 

"You might as well stop acting all shy and nervous. As I said, we'll be together for a while."

"Sorry, sir."

"Now, come with me. I'm gonna find you some stuff to wear until this is over."

As they walk to Levi's quarters, the older man can't help but be confused by Eren's bashfulness. It's normal to be shy around commanding officers, but Eren is only this jittery around Levi. Eren has so much confidence around others his age and even the rest of the corps. It makes sense since he's been with them for a little over a year. 

He shouldn't be paying any mind to how Eren feels about him, but it would be nice for the brunet to at least be able to talk to him without mumbling or stuttering. 

_ Maybe he's nervous because you beat him half to death,  _ Levi thinks to himself, clicking his tongue at his own ignorance. Eren is traumatized, clearly, regardless that Levi has explained that the beating was to save his life. 

Levi stops walking, and clearly, Eren isn't paying attention, so he walks into Levi's back and knocks himself back, falling onto the ground with a dull thud. 

"Ouch..." Eren mumbles, standing abruptly to conceal his embarrassment. "I'm sorry, sir."

Levi clicks his tongue again, pulling his key from his back pocket and unlocking the door to his quarters. 

"This is really nice, sir," Eren says as he steps inside, looking around the room in awe. "I've never seen such a pretty room, sir."

"I intend on it staying this way, so don't go dirtying up my room unless you plan on cleaning it until your hands bleed."

_ This is probably why he's afraid of you, dumbass. You're always so condescending. _

Eren sits down in an empty chair. The poor kid looks like he has a stick up his ass.

"You can relax, brat," Levi grumbles, walking over to a dresser and opening one of the drawers. "I'm not going to hit you."

He pulls out a shirt and a pair of sleeping shorts.

"These will be more comfortable to sleep in. Change."

"H-Here, sir?"

Levi rolls his eyes.

"You can go to the bathroom if you want. You might as well shower too since it's about bedtime."

"Yes, sir."

Levi watches as Eren scurries off to the bathroom. The shirt has ridden up, showing the tight briefs that Eren is wearing. 

Too tight in Levi's opinion. The kid's ass is on display for the whole world, and it looks like the underwear is cutting off the circulation to his thighs.

His ass does look nice, though. Nice and round, jiggling as he walks. He'd be lying if he were to say he didn't enjoy the sight--

Levi shakes his head, groaning and standing to strip himself down to his underwear. Hopefully, there's enough paperwork to keep his mind off the kid for the night. 

It's about thirty minutes later when Eren comes out of the bathroom. The shirt is substantially shorter than the one he had on previously; if he were to raise his arms, half of his stomach would likely be exposed. The shorts are tighter than Levi expected, and he can tell that the brunet isn't wearing any underwear.

All the paperwork in the world wouldn't be able to keep Levi's mind away. 

"Sir, I was wondering if-- Oh my goodness!" 

Eren simultaneously blushes and goes pale when he realizes that the older man is shirtless. He stares dumbfounded, mouth open and eyes wide.

"Have you never seen another man half-naked before?" Levi asks, half annoyed but half-amused at how flustered Eren is. 

"It's just that you had more clothing on before I left, so I was surprised to see you lacking those clothes. I'm sorry, sir. "

Levi clicks his tongue. 

"Whatever, brat. Just get in bed. Be glad that I'm not making you sleep on the floor."

"Thank you, sir," Eren almost whispers, nervously walking over to Levi's bed. The brunet stiffly gets under the covers. Levi turns off the light gets in on the other side. 

Even though his back is toward Eren, he can feel viridian eyes boring into the back of his head. He doesn't say anything, hoping that Eren will speak up first.

There's an obvious tension between them, whether it's sexual or just nervous, though Levi hopes it's the former rather than the latter. 

"Captain... Can I ask you something?" Eren whispers meekly, voice trembling.

"What is it, Eren?" the older responds, turning to face the boy.

"Do you dislike me?"

Levi is surprised at the question. Though he tends to be aloof and cold to everyone, he doesn't just  _ dislike  _ any of the soldiers in the corps. Besides, Eren hasn't given him a reason to dislike him except for the fact that he haunts Levi's thoughts on lonely nights with his desperate moaning and pleads for release and--

"What makes you think I dislike you?'

"Well, you're always... mean to me. Whenever you talk to me, you're snappy, even when I haven't done anything."

"I'm snappy at everyone, brat. What makes you think you're going to get special treatment?"

"I'm sorry, sir. I didn't mean to upset you! It's just... everyone else is nice to me, but you're just weirdly mean and--"

"What? You think you can waltz your cute ass into the corps and bat your wide eyes and think that everyone is going to treat you like royalty?" Levi is starting to get pissed off. He can't understand why Eren is so adamant; he'd heard that the brat was stubborn, but this is nothing like he expected. 

"I-I never said that! It just hurts my feelings that you dislike me for no reason, sir!"

"I  _ have  _ a reason for disliking you!"

"What is it then? Tell me so I can fix it!"

Levi has to bite his tongue to keep from exposing himself. He'd already called the boy cute, and he is desperately hoping Eren hadn't heard it.

His hope starts to fade when a dainty hand reaches out to cup his face. Levi flinches but doesn't back away, allowing Eren's warm hand to rest on his face.

"Is it that... you are attracted to me, Captain?" Eren asks, eyes wide with curiosity.

"That would be against protocol."

"When have you ever been known to follow protocol, Captain? It's okay if you think I'm pretty."

"Pretty? What are you, a girl?" Levi snorts, trying to take the heat off him. His attempt is futile when Eren scoots closer, close enough to breathe the same air as the older male. 

"I would be a girl if it meant I could be yours," Eren whispers with an oddly suggestive tone that Levi didn't even know he was capable of. "How hard would it be for you to just forget about protocol, even just for one night?"

Before Levi can respond, Eren presses their lips together.

The kiss, though chaste, is mind-blowing to Levi. Eren's pink lips are unbelievably soft and warm, making Levi's cock jump in his boxers. The hand that is cupping his face is joined by another warm hand. Levi moves to wrap his arms around Eren's waist, pressing to deepen the kiss.

Eren's doll-like eyes flutter closed when Levi deepens their kiss. They move their lips slowly at first, becoming accustomed to each other's taste and kissing style. 

Soon, Levi becomes impatient. He parts his lips slightly to swipe his tongue across Eren's bottom lip, asking for entrance. The brunet immediately obliges, opening his mouth excitedly. When Levi's tongue makes it past Eren's lips, Eren's tongue is already waiting.

Their appendages slide against each other wetly, fighting for dominance though Eren doesn't put up much of a fight. 

Levi's hands slide down to grope at Eren's plush ass, making the boy whine into their kiss.

When the need for oxygen becomes too much to ignore, they part with a smack. Levi cranes his neck to suck at Eren's jaw and nip at his blushing ears, making Eren thread his fingers through Levi's hair. 

"God, I want to fuck you, Eren," Levi groans against Eren's ear, using his grip on Eren's ass to press their crotches together and grind their clothed cocks. "Do you want that, Eren? Do you want me to stuff you full of my cock and pound you until you're begging for release?" 

"Fuck me, Captain. I want your cock inside of me, please," Eren moans, nodding his head enthusiastically.

Levi pushes Eren onto his back and climbs on top, reluctantly sliding his hands away from that glorious ass to pull his own boxers off. Eren follows suit, stripping himself.

Once they're both naked, their hands are back on each other's skin, mapping out planes of hardened muscle and soft, smooth skin.

Eventually, Levi's hands have to move away to rummage through a drawer, pulling out a large tube of lube. 

"Spread your legs and put them over my shoulders," Levi commands, sliding between Eren's thick legs. Eren obeys.

"Are you a virgin?"

Eren shakes his head. Levi is damn glad. No nervous fumbling or waiting for Eren to adjust to the feeling of fingers in his ass.

"Good. I'm going to start with two fingers. Tell me what feels good and what doesn't."

After dispensing some of the clear liquid onto his middle and ring fingers, Levi reaches under Eren to probe at his hole. Eren's breath hitches at the coolness, and he gasps when the tips of Levi's fingers press into him. 

Eren is no fool. He is already cleaned and stretched, so Levi's fingers slide all the way in with little resistance.

"Look at you, little minx. Cleaning and prepping yourself, already expecting to get fucked," Levi whispers into Eren's ear. "I was thinking that you were shy and innocent. You're nothing of the sort, are you?"

He starts to scissor his fingers, meeting little resistance. His cock twitches at Eren's hot moan.

"I'm going to fuck you so hard," Levi adds, inserting a third finger alongside the first two. Eren's hole is slick and so hot, accepting the fingers with eagerness. 

"J-Just fuck me, Captain!"

"Beg with my name."

"P-Please, Levi, fuck me until I can't think! I-I want your fat cock so bad!"

Levi would have never pinned Eren to have such a filthy mouth.

With a smirk, Levi slides his fingers from the tight hole. He uses the excess lube to coat his cock.

"You ready?" Levi asks as he lines his tip up with Eren's hole. The brunet moans in response, hands sliding up to grip at Levi's shoulders.

Slowly, Levi begins to push in, letting out a deep groan at the tightness around his cock. He'd forgotten that Eren's body is hotter than other people, so he's surprised at the heat that accompanies the tightness. 

"Fuck, Eren, you're so damn hot inside," he rasps into Eren's ear, nipping at the lobe to pull a moan from the brunet. Eren claws at Levi's back as the raven makes it halfway in.

"S-So big!" Eren responds, arching his hips up to take more of Levi in. 

"Don't be impatient, brat. You'll get all of me soon. Just let me-- fuck-- go slow."

Eren doesn't listen, his hands sliding down Levi's back to push at his hips.

"W-Want more! Give me more, Levi!"

Levi growls and slams the rest of the way in, catching Eren off guard and forcing a drawn-out moan from plump lips. The older pulls out and slams back in, feeling Eren's nails bite at his lower back.

"You want more, you little slut? I'll give you more. Don't complain if you can't walk tomorrow~" Levi purrs, pushing and pulling his cock in and out of Eren at a bruising pace. The brunet can't do much else but hold on for dear life and writhe beneath him.

"F-Fuck!  _ Yes, Levi! _ K-Kiss me, please."

Levi cranes his neck down, roughly smashing their lips together. The kiss is less of a kiss and more of the tangling of tongues, but Levi is more than happy to slide his appendage along Eren's. 

Suddenly, Levi hooks his hands in the bends of Eren's knees, pushing the boy's knees to his ears to plunge deeper into his wanting hole. 

"Look at you, all pliant and flexible for me."

"L-Levi! T-There!" Eren sobs, throwing his head back and effectively breaking their kiss. 

"Oh? Is this your spot?" Levi asks rhetorically, already knowing he's found Eren's prostate. To emphasize the question, he pushes his hips faster, drilling into the spot with deadly accuracy. If Eren wasn't screaming before, he definitely is now. Tears of pleasure start to roll down Eren's face, and his flushed face goes darker.

"G-Gonna-- L-Levi!"

"Gonna what, Eren? Use your words," Levi teases, leaning down to suck at Eren's neck.

"Gonna cum!"

"No, you're not," Levi counters, slithering a hand to Eren's cock and squeezing the base. Eren writhes beneath him, his head thrashing from side to side. Levi only continues the punishing pace with his hand around Eren's cock, watching and listening as the brunet becomes more desperate to cum.

"Levi,  _ please!  _ I w-wanna cum! Wanna cum,  _ please _ !"

"Have you been good enough to cum, Eren?"

"Y-Yes! Yes!"

"Cum for me then, Eren. And call my name while you do it. I want everyone to know who's making you feel like this," Levi groans, jerking Eren's cock as he drills into the sobbing boy's prostate. 

Levi watches in awe as Eren's back arches up off the bed, and his eyes squeeze shut. The brunet's plump lips form an 'O' shape around his overstimulated moans and sobs, hot cum striking his stomach and Levi's hand. 

After such a display, it only takes Levi a few more thrusts before he pulls out to cum on Eren's stomach, gripping Eren's leg to stay grounded.

"Fuck!" he groans, pressing his lips to Eren's. The brunet kisses back weakly, whimpering.

Levi's orgasm soon ends, and he flops down next to Eren. The older man reaches over to his nightstand to grab a wet wipe, cleaning the cum off Eren's stomach. He pulls the covers over them both, pulling Eren into his arms.

"Thank you, sir," Eren mumbles, blinking up at Levi with sleepy eyes. At one point, Levi would've thought it to be an expression of pure innocence; now, though, he knows better. 

Levi feels very taken advantage of. 


End file.
